Question

Assertion : When the force retards the motion of a body, the work done is zero. Reason : Work done depends on angle between force and displacement.​

Answer 1

Answer:

both are true and reason is the correct explanation for assertion

Explanation:

When the force retards the motion, the work done is negative.  Work done depends on the angle between force and displacement W=Fscosθ

Answer 2

The Assertion is false but the Reason is true.

• Work done is a scalar product of the force applied and the displacement of the body.
• Mathematically, W = F s cos∅. Here ∅ is the angle between the force and the displacement.
• The work done is positive if both force and displacement are in the same direction.
• When the force retards the motion of the body, the direction of force and displacement is opposite. Hence, work done is negative.
• If the displacement and force are perpendicular to one another, no work is said to be done.